The three scholars consulted — E. De Felice, E. Rossoni, and G. Rohlfs — agree that this surname is rooted in the Latin form Marcianus, though they differ on the specific etymology and geographic distribution of its variants.

De Felice traces the surname to place names of the type Marciano or Marzano, found throughout Italy, formed with the Latin predial suffix -anum. In the Griko-speaking areas of Calabria and Sicily — that is, areas of southern Italy where varieties of medieval Greek survived — this suffix was adapted as -anò, following the model of the Greek and Modern Greek suffix -anós.

Rossoni distinguishes between the two principal variants. Marciano, in his view, belongs to the province of Naples and derives from the place name Marciano or from Marcianofreddo, both located in the area of Caserta. Marcianò, by contrast, shows two areas of concentration in Sicily: one in the area of Messina and another in the area of Palermo. For this accented form, Rossoni also proposes an alternative etymology: it could derive from the Latin gens Marcia, a Roman family said to have held properties in Sicily.

Rohlfs approaches the surname from a Greco-Byzantine perspective. He documents it in Catanzaro, Cosenza, and Reggio Calabria, as well as in localities within their provinces — Mèlito, Crotone, the area of Squillace, and Rogliano — and notes its presence in Sicily as well. According to Rohlfs, the surname derives from the Greek Markianòs, the equivalent of the Latin Marcianus, a personal name that enjoyed wide diffusion in the Byzantine sphere.

It is also noted that the surname may derive from the Latin given name Martius, meaning "sacred to Mars," or from place names such as Marzano or Marciano.